Best available cop



Dec. 20, 1927. 1,653,158

W. L. ECKHARDT RADIO REPRODUCER Filed July 9. 1926 INVENTOR A TTORNE Y.

ym WW Patented Dec. 20, 1927.

UNITED s ATEs PATENT OFFICE.

WALTER L: ECKHABDT, Y or. PHILADELPHIA, PENNSYLVANIA.

- ,1 ii; 152%.. 3 21 :3... u.

f B ADIQREPRODUCERQ .ii u auu magma, are. semi 116. 213.

My invention relates to sound reproducing devices comprising' a diaphragm ,asso eiated with a 'resonant'iinitl'and with means for efi'ecting vibrations 'of the diaphragm in a mannerto reproduce: the modulations of the sound waves which have been impressed upon the vibratorymember by which .Vibifilf tions are imparted to' the dltlphl'a'gmj My inventin relates essentially to the diaphragm and it has for itsgeneral' object to provide a diaphragm lofnovel construction ndu in r ea vhf r we madam: tions ofjthevibratoryj 'infpose'd' the tfrj on by.'tlie'sou ii,w vs whiehfar' toibe rep-ragdiioed "are" accurately and "faithfully reprd: ducve d.*. 1).. J Z. win-H'- i,- he;

It also is 'an'object'ofthe'invention .to pro} vide a construction .ofradio reprod ucer' including e e y:a aae mu o prisi a plurality of independently vibratable inemf bers, thereby afi'ording means whereby an ac'curatel'freproduction of unditv'a'vej may 5on1: 5 i li ;l,..ii..;

Ahothenobject of the nventidn is to f a iri nii iq fiu'cti n wh fihet the'extent or areadr the di aphiagm ma yfbe increased or diminished, as maybe desired or 'r equ-ired to meet onditions "as' they a rmt e F T '9 "1 furtlierfobject of the invention s ."to' provide a 'i a'dio reproduce? L I Pii Sing'a resonant member'and a diaphragfnfl'respec tiv ely "including means of novel whereby they are adapted tdcodperat' tb reproduce the and most delicate modulation of; fwave s which ma be imposed thereon'.* i t Y To these and other ends my inventioii'cor'm prehends the construction, and arrangement as hereinafter described' in detail;- .p'articu larly pointed out iii' 'theiclaimsia'rid as illustrated in the drawing in which]: have 'shown one form of aconvenient' embodiment of the invention. However, it will be' understood that the inventionissusceptible of embodimerit in other forms of construction than that shown and that changes in thefl'details of construction'may be, made within the 'scopefof the claims 'without departing from the invention. f

In thedrawingi v Fig. 1 is a viewiin front elevation of a radio reproducer embodying the invention,

the closure of fabric or other material shown in Fig. 2 being omitted;

iFig. 2' is' a vertical sectional view taken on thelineQ -Z of F i'g. 1'; and v 'Fig ."3 isf'a sectional view through the centralportion of the diaphragm with the partsenlarged'so as to show more clearly the details of construction. U

'Be ferringjto the drawing, 1 d'esignate's a Base of relatively large dimensions and pref erably of wood, upon which is-mounted a shorteif"port ion 2; also 'of wood, to which i "s" 's ecured a resonant member 3 of wood liiq s' a .1 m. u r. r 1 1iiember*'3"may be made up, asfusuah'of a number of thin sheetsf glued 'o rgotherw ise secured together. On 'e 'end 'of theinember 3 may' be' c losed by a wooden sheet '25 which constitutesa sounding board which' cooperates with the"diaphragm which will be hereinafter described. Mounted within the member 3 adjacent one end thereof and in prox'imitytoi the wooden sheet 25 is a bers ai' of'the' shape 'of isosceles triangles,

as 'shown,f"'lhey may consist of thin paper or parchnijentor' othermaterial of'any charactr ivh'i'chihity be found T to .be satisfactory. The members 7 may. varyin thickness and stiffness 'and"consequently in rigidity. It has been'ffoun'd that by employing a plurality' of 'members in 'the construction of diaphragms for radio reproducers thesaid reproducers may be'adapted for the receipt and reproduction 'of musical .pieces "arying in their characteristics; that is to say, a reproducer having a diaphragm of one constructiom'has been found to be more satisfactory itor the reception and reproduction of certain musicalpiece than another reproducer containing another or' difierent construction ofdiaphragm in which the members 7 were ojfjdifierent thickness or rigidity.

Also, by the employment of a diaphragm comprising a plurality of members, as illustrated, which overlap each other, as shown .in'I'ligfl of the drawing, the area or amount of vibratory material may bevaried.

In the securingof the members 7 to the resonant member 3-it will be noted that the corners of the triangular members at the bases thereof rest upon the inclined surface thereto by means of a relatively narrow clampingrim I0. Qbviorislyg theicorners oi the Vibratory members 7 may 'besecured to the resonant member 3 in any other manner which may beiproferred nnidesiredzqspaces of segmental shape are formed between the bases of the triangular members 7 a'till tli opposing portions of the drum 3, The members 7 are inclined towa'i'ilthe end" tfi e re e etimeei 3uee en e wate the"'axi" therof'"as s fe giar y e mwn. Th ,e ip l eift ree af-a are? rd e w is extei'nis in r zre slitasia v o gn raa tet i ar s i gta ligas 3, ji c 1; iieq'araihatitiii. ar th y (persist d; a s t the e .as, ts tbsasneitns be anex a e 'th t eeeess ee s s t etihae et mnee ein or e s 'ytbe i ed w film Mi limits-=19 i dependentfof each z'l fi' i .1165..- fi i othe zli b e fl'qi e e bi i h t thickness thereof mayb yaried 51 that to say,i certain of the imbeis ma consist i hBet ma eot-9m a i i hile. oth r e bemma c n tof uch, material: of a diff re t it k SSQ-"BY at a bnlo e ability to my e h j e s bfi i she s-twee tuting the {members 7 ,aaidtq .y -irytl eextent of oye'rlapping of the said Sl 1e et great flexibi i y of e n t uc q n s'pb ib e,t ereby,.e r a;b1ing 'the production of ,repiioducers suited to 1 the reproduction of musical or other sounds of different and yarying'character- 'For the purpose of effecting or causing vibratory movements or themem'bers7'of the diaphragml' have provided a loud speaker unit, indicated as a vhole fat 20,- which may be of" any known construction, from the V1- bratory element of whichek'tends a'reed 21, the outer end of 'whichjia'sse'sthrough the axial hole 22 through the binding member 12 and is' secured in place therein by means of 'a binding screw 23. The loud speaker unit is mounted upon the sounding board Current jo r energizing the loudspeaker unit.

passes through" the conductor 26.

The end of the resonant member 3 oppo- Ivasite-thesoundmg-board may be closed by means of a sheet of fabric or other suitable iniit e rial Q7 having a spring wire 28 in its onter edge which is adapted to fit within the interior of one end-of the said member.

Itwill be seen that by my invention I have provided a diaphragm of multiplex charactei'jhereby great flexibility of construction isobtained. Such'yariati0n may be effected v by Varyingthe lengtli of the bases of the triangular members '1'; byvarying the thick} ric s sfolf the sheets io f which the said members consist "and by 'varying the m erlapping lationshipfojf the said members to eacnother ,thereby" yarying the; area or extent of the,yibr atoryf"element a'sawhole.

j'l hisoundsfpr'oduced by the vibration of the soundingbos'rd areallo ed w' pass freely pastjaiid beyond the diaphragm bje' i or a cause 7 of thef presence of the spaces of 'seg-j mental sliapebet'ween'the bases of the ine'nijher 3 e 9; s rees o -e n of san teamed ay 'i-aaaamm i l l'fcla'i'lii 'and desire gto 'secnre byLettersfBat lfA radio reproducer comprising 'diaphragm of multiplex character, the,. inner ends of. the members of which .are'oyerlappedand secured together, and tlie uter p "rtions, of iybich are connected to, a' resoi all iii m rlff J U A ra dio .ii'ep'i'oducer l comprising a diaphragm consisting of a plurality of sheets of material which converge. toward a central point and the inner. ends ofwhich" overlap each other and are'secured together, and the outer. portions ofwhich are secured to a respnant member.

3. A radio reproducer comprising a diaphragmconsistin of a plurality of triangular members of s eet material, which members converge toward a central point and the apical portions of which overlap each other at saidfcentral point, means for securing the said apical" portions together; and the cor- 11ers at the bases of said triangular members being mounted upon and connected to a resonant member.

1; A radio reproducer comprising, in combination; a. resonant member of drum shape, a diaphragm consisting of a plurality of sheet members of triangular shape, each of which is connected at the corners of its'base to the saidresonant member, and the said triangular members extending "inwardly and in a direction toward an end of thesaidresonant' member, the inner end portions there- 'of' being bent reversely and then extended horizontally into overlapping relationship with respect to each other, means for securing the overlapped portions together, and means for connecting a loud speaker unit to the overlapped portions of the said diaphragm members.

5. A radio reproducer comprising a diaphragm consisting of a plurality of sheet members, of isosceles triangular shape, which members are adapted to overlap each other and the corners of the respective members at the opposite ends of the bases thereof being connected with and supported upon a resonant member, said members converging toward the axis of the said resonant member and also toward one end of said member, and the apical portions thereof overlapping each other in line with the said axis, and means coincident with the said axis for fastenin the said apical portions together.

6. 3 radio reproducer comprising a diaphragm of multiplex character, the inner ends of the members of which are overlapped and secured together, said inner ends being separated by washers, and the outer portions of which members are connected to a resonant member.

7. A radio reproducer comprising a diaphragm consisting of a plurality of triangular members of sheet material, which members converge toward a central point and the apical portions of which overlap each other at said central point, Washers located between the overlapping apical portions, means for securing and binding the said apical portions and the said washers together, a resonant member comprising a portion of drum shape, and means for securing the corners of the said members at the opposite ends of the bases thereof to the said drum shaped portion of the said resonant member.

8. In a radio reproducer, the combination of a resonant member comprising a drum and independent members of sheet material mounted at their outer ends upon the said drum shaped portion, said diaphragm comprising a plurality of independent members each of which subtends spaces between its outer end and the said drum shaped portion, and the said members converging toward the axis of the said drum shaped member and overlapping each other in the line of said axis, and means for securing the overlapped portions together, substantially as described.

9. In a radio reproducer, the combination of a resonant member including a drum shaped portion and a sounding board closing one end thereof, a diaphragm mounted within said drumshaped portion, said diaphragm consisting of a plurality of triangular members, the corners of Which at the opposite ends of the bases thereof are secured to the said drum shaped portion, and the said triangular members extending toward the end of the said drum shaped portion opposite the said sounding board and converging toward the axis of the said drum shaped portion and overlapping each other in the line of said axis, and means for securing the said overlapped portions together, substantially as described.

10. In a radio reproducer, the combination of a resonant member comprising a drum shaped portion and a sounding board mount ed thereupon, and a diaphragm consisting of a plurality of separate members mounted upon the said drum shaped member and extending transversely thereof and in opposed relation to the said sounding board.

In testimony that I claim the foregoing as my invention, I have hereunto signed my name this 2nd day of July, A. D., 1926.

WALTER L. ECKHARDT. 

